Negative Pressure Ventilation

[Sasha]

Isn't it amazing what you find when you wander the internet?? I was helping my cousin research polio for a school project and some interesting info and figured I'd share with the class (website.). It is not directly EMS related since I don't see how it could be done in the field, but good information none the less.

Negative pressure ventilation in the treatment of acute respiratory failure: an old noninvasive technique reconsidered.
Link: http://www.ncbi.nlm.nih.gov/pubmed/8836670
Full PDF: http://erj.ersjournals.com/cgi/reprint/9/7/1531

Noninvasive mechanical ventilatory techniques include the use of negative and positive pressure ventilators. Negative pressure ventilators, such as the "iron lung", support ventilation by exposing the surface of the chest wall to subatmospheric pressure during inspiration; whereas, expiration occurs when the pressure around the chest wall increases and becomes atmospheric or greater than atmospheric. In this review, after a description of the more advanced models of tank ventilators and the physiological effects of negative pressure ventilation (NPV), we summarize the recent application of this old technique in the treatment of acute respiratory failure (ARF).

 

[VentMedic]

The articles you found are from 1996 which is "old news" in the world of technology but nonetheless these devices still exist and are being more readily accepted in certain populations. They also got a new look from the FDA last year for approval for different applications in this country.

You may come across these devices, usually the Cuirass, in the homes of adults and children with chronic diseases such as CF and Muscular Dystrophy. We also had a young spinal cord injured patient who did not want to be trached again that has had success with Negative Pressure Ventilation at home.

I met Mr. Emerson, yes I am "old", at a seminar many years ago. He had developed the Iron Lung in the early 1900s which at that time was a marvel of modern medicine. For a demo of a simple solution to a complex problem, he placed a vacuum hose on a 5 gallon water bottle. The Iron Lung was just one of his inventions as he made a large contribution to what is now modern respiratory technology. He even designed a PEEP valve (water column) to which the concept would later become a valued asset to modern ventilation and later hit the streets as "CPAP".

Video of the Cuirass:

http://www.mediventintl.com/film_presentations.htm